A. Field of the Invention
The invention relates generally to redundant switch configurations, and more specifically to redundant switch configurations that provide both signal loss protection and equipment failure protection.
B. Description of the Related Art
For fiber optic networks, problems in transmitting and receiving signals may be due to equipment failure, such as switch failure, or it may be due to failure of the signal lines, such as the fiber optic lines which provide signals from a source to a destination.
Typically, conventional optical communication systems comprise a receiving node and a transmitting node (Baltimore, Md. and New York, N.Y., for example) connected via optical fiber. Each node contains equipment for communication via optical fiber. Such equipment may include channel equipment and Wavelength Division Multiplex (WDM) equipment. Channel equipment is equipment that transmits and receives via a specific wavelength (or channel). In a conventional system, if a fiber is cut resulting in a loss of signal, the system requires a network element (such as a SONET processor) to determine there is a failure in the digital domain and notify the switch to change state.
Further, switches are utilized to direct signals transmitted by the nodes to various fiber optical cables within a conventional optical communication system. When a switch fails in a conventional system, an operator manually reconfigures the switch to communicate via an alternate channel. The resulting down time from manually switching channels results in a high amount of data loss and an inefficient use of backup resources.